Professional training is the most common usage of extended reality (XR) technologies in enterprises. For example, Walmart has used virtual reality to train more than one million employees. The immersiveness, interactivity, and realism offered by XR-based professional training make it more effective and engaging than traditional flat training media such as instruction manuals and videos, leading to a reduction in training time and a significant improvement in performance. The convenience, safety, scalability, controllability, and low-cost nature of XR-based professional training also make it highly promising as an approach for public service training, fitness training, home-schooling, and rehabilitation. While XR-based professional training is promising, a number of technical challenges need to be solved to facilitate its widespread adoption and effective use. Through this research topic, we aimed to articulate visions on overcoming the research challenges of using extended reality technologies for professional training purposes. We accepted research papers in a variety of computer disciplines related to XR-based professional training and content creation to inspire the field to further explore this promising direction.